The side wall flashing problem and solution
Common rot spot
The intersection between a roof and a sidewall can be a rot problem waiting to happen. Even if the roof has been properly flashed against the sidewall (this one hasn’t), water can still run down the side of the house and behind the siding, causing rot.
The solution to rotting sidewalls is a small piece of bent metal called a kick-out flashing (at roofing suppliers), which simply directs all that water away from the wall. It installs just like standard step flashing, except that half of it hangs over the edge of the roof.
Install the flashing
Photo 1: Slip in the flashing
Lift the bottom shingle and slip in the kick-out flashing. Nail it to the sidewall (or glue it if nailing isn’t possible).
Photo 2: Cover with cap flashing
If the kick-out and step flashing can’t tuck behind the siding, screw on cap flashing to cover it, then caulk along the top.
Inspect the sidewall around and underneath the fascia and inside the house for signs of moisture damage, and repair any rotted areas. Add felt, if needed, before nailing the new wood on, and prime the new wood on all four sides before installing it.
Install the kick-out flashing underneath the first shingle (Photo 1). If the shingle already has flashing on it, the kick-out flashing has to slip beneath it, and you’ll have to loosen or remove siding to do this. If the sidewall is stucco or solid wood like ours and you can’t open it to get flashing behind it, continue the step flashing to the peak of the roof, then cover the step flashing with cap flashing (Photo 2).
Required Tools for this Project
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
- Caulk gun
- Drill/driver - cordless
- Pry bar
- Tin snips
Required Materials for this Project
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here’s a list.
- Cap flashing
- Exterior caulk
- Kick-out flashing